Squid download limit is not working with user access groups


After upgrading squid-3.0.STABLE20-2 to squid3.1 , Authentication error occurred. Cache log shows the following error message

Squid download limit stopped working

AuthNTLMUserRequest::authenticate: attempt to perform authentication without a connection

Then I verified my ntlm_auth in squid.conf file, everything was perfect.

After commenting the following lines, squid started working.

#acl group1 proxy_auth user1 user2
#acl group2 proxy_auth user3 user4
acl group3 src 10.5.2.5 10.5.2.10
#reply_body_max_size 204800 KB group1
#reply_body_max_size 104800 KB group2
reply_body_max_size 10480 KB group3
reply_body_max_size 5120 KB all

Squid download limit is not working with user access groups and it is only working with ip access groups,
Anybody have successfully configured in version 3.1